Improvement in bit-stocks



idw-rd' tstrs aan eine.

Letters Patent No. 106,754, dated August 23, 1870.

IMPROVEMENT IN BIT-STQCKS.

' The Schedule referred to in these Letters Patent and making part o'the same.

To all whom) it may concern Be it known that I, CHARLES I. WHITMAN, of Charlemont, in the county of Franklin andState of Massachusetts, have invented certain Improvements in BitStocks, of which the following is a specification, reference being had to the accompanying drawing.

My invention consists iu certain improvements inA the heads or jaws of bit-stocks, for securing the bits or other tools to the stock, as hereinafter def scribed.

Figure 1 isl a side viewof a bit-stock having my improved head applied, and a bit secured therein;

' Figure 2 is a vertical section through the center of' the head, with abit secured therein Figure 3, the same, -with the head unscrewed and the bit released and partially withdrawn; f

Figure 4, a cross-section of the head on the line y y; and

Figure 5, a section of theend or neck of the stock,

s howing., r the socket therein.

The body of my stock I construct in the usual manner, except its lower end or neck, which I provide, onA the outside, with a screw-thread, a, and in its end with a' square recess or socket, b, madc ot' a taper form at its outer end.

Into the back end vof the socket b I insert aspira] spring, c, and in front of the spring place a tubular thread cut upon its interior, and ot' the proper size to lit upon the end or neck a of thc stock, thc opening in the front-'endet' the head being reduced in dialneter so as to form on -the inside an annular ange or shoulder, f, assh'own in figs. 2 and 3.

In one side of the head B, I cut a recess or opening, extending from the front end back about midway of the head, and in this 'opening I pivot a jaw, C, which 'may be turned outward, as in tig. '3, sc as to leave an opening in the side of the head sufficient to allow the insertion of a bitshauk, or which may be closed so as to be iiush with and form a continuation ofthe head, as shown in gs. 1, 2, and 4, the jaw being provided with a shoulder to correspond with that in the head.

When the jaw C is closed and the neck screwed bark onto the neck a, the back end of the jaw C is carried outside of the neck, and thereby the jaw locked shut, as in iig. 2, but upon again turning forward the head until the end ot' the jaw clears the neck, the former is released, and may be reopened, as in fi". 3..

T3 insure the closing of the jaw when the head B is turned up, I bevel the inner side of the -back end of the. jaw, as shown in iigs. 2 and 3, Vand also bevel the outer edge of the end ofneck a, as shown at n', fi r. 5. The opening in the side of the head B, I make of sufiicient size to readily admit the Shanks of ordinarysized tools, and the opening n, through the end inside of shoulder f, of' suicient size to admit the stem but not the Shanks of the same. When it is desired tosecure va bit-or other tool in the stock, the head B is unscrewed until the jaw C is released, and the end of the jaw then turned out, and then the shank 'of vthe tool inserted through the side-opening, so that its shoulders engage behind vthe ange or shoulder fof the head, and the jaw C then closed.

The head B is then screwed up, when -the shoulders of the head and its jaw forcethe shank back into-the socket b, and thereby secure the bit rigidly in place.

The chuck d is held by the spring so far forward that whenever a tool is inserted into the stock the end of its shank enters the hole in the chuck, which 'latter is forced back until the forward -portion of the shank bears upon the sides of the socket, as shown in tig. 2, so that, when the shank is seated, its rear end is centered and heldby the chuck, and its forward or large end by thesides of' the socket.

Thus it will be seen that, whether the shank of the tool inserted is large or small, long oil short, or of the same ora dierent taper from the socket b, it will,v by means of the sliding chuck, lbe afforded a solid bearing in the socket, \vhile the -ange of the head'- as set forth.

CHARLES P. WHITMAN.

Witnesses:

F. E. Nuus, H. M. BUFFER. 

